The present invention relates to an introducer and method for treating a branched lumen and more particularly, an introducer and method for implanting an intraluminal prosthesis having a trunk and at least one arm into a branched lumen, such as the aorta and the renal arteries.
Introducers for implanting prostheses or grafts, such as for repairing aneurysms, are well known for medical practitioners. These introducers essentially comprise a catheter with an inflatable balloon at a distal end thereof. The graft is typically wrapped over the deflated balloon and the catheter-prosthesis assembly is disposed within an outer sheath for insertion into a blood vessel. The introducer is moved along the vessel until positioned in a desired location in a portion of the vessel to be repaired. Once in position, the sheath is retracted to expose the graft-balloon assembly and the balloon is inflated by pressurizing the catheter with fluid. During inflation of the balloon, the prosthesis is expanded and implanted in the vessel wall. The implantation is facilitated by use of intravascular devices called xe2x80x9cstents.xe2x80x9d A stent is a mechanical scaffolding that is typically sutured to the graft and that is expanded, for example by deformation from a compressed diameter to an expanded diameter by inflation of the balloon. The stent, once in its expanded shape against the internal side of the blood vessel, is resistant to compression and therefore holds the graft in place.
Many prostheses known in the art are implanted by means of an introducer having an elongated balloon or a pair of balloons each located at respective ends of the cylindrical prosthesis. Others comprise two or more portions that must be assembled inside the blood vessel, for example to repair a bifurcated length of the vessel, such as the bifurcation of the aorta into the iliac arteries. So-called xe2x80x9cmodularxe2x80x9d grafts comprising two, three, or more portions are typically implanted by installing one portion at a time and connecting the portions to each other while in situ inside the lumen.
FIGS. 1 and 2 show a diagrammatic view of a typical catheter 1 of the prior art. Catheter 1 typically has two lumina extending axially through the catheter: a first lumen (not shown) for sliding the catheter over a guide wire 2, and a second lumen (not shown) concentrically encompassing the first lumen and in fluid communication with a radially-expandable balloon 3. Prosthesis 4 is schematically shown wrapped over balloon 3. Prosthesis 4 comprises one or more stents 10 (shown in FIG. 2) to be expanded against a vessel wall for implantation. The catheter-prosthesis assembly is mounted within sheath 6. Nose cone 5 is provided at a distal end of the introducer. The purpose of the nose cone is to provide a smooth, soft tip for preventing injury to the blood vessel as the introducer is manipulated and pushed through the body lumen to reach the desired location. Nose cone 5 also closes off the distal end of the introducer to prevent blood from entering into the introducer.
At the proximal end of the introducer, the first and second lumen branch out at angular piece 7 forming an outlet 8 for wire 2 and a connection line 9 connected to a valve (not shown) for supplying the pressurized fluid into the second lumen for inflating the balloon.
FIG. 2 shows introducer 1 after having been moved along lumen 12 until reaching a deployment location, such as an aortic aneurysm. Balloon 3 is inflated to exert a radial expanding force from inside prosthesis 4 to radially deform stent 10 until it is implanted against the interior side of a distal portion 11 of lumen 12, such as an upper neck of an aorta affected by an aneurysm. Guide wire 2 serves to guide the insertion of introducer 1 as well as to assist in positioning graft 4 and stent 10 in the desired location for inflating balloon 3.
There are, however, situations where a vessel has, in a section thereof, a junction with one or more branch vessels, such as the junction between the aorta and the renal arteries. A graft for implantation at such a junction, such as for repairing a disorder at the junction of the aorta and renal arteries, requires a different introducer and different deployment method, as a branched graft cannot be implanted without being able to access the aorta and the renal arteries simultaneously to connect the several portions together. Thus, the introducer shown in FIGS. 1 and 2 would be inadequate for such an implantation, as the complex shape of the necessary prosthesis requires multiple guide wires, and any maneuver to attempt to implant such a complex graft using this introducer would be tedious, difficult, complex and time consuming, if not impossible.
Therefore, there is a need in the art to provide an introducer and implantation method for implanting a modular or unitary graft into a branched lumen, such as at the junction of the aorta and renal arteries, by a simple, easy and safe way, taking only reasonable time for the safety of the patient.
The various features and advantages of this invention are better understood when taken in connection with the accompanying drawings and description. The present invention comprises an introducer for insertion in a lumen from a proximal location outside the lumen to a distal location within the lumen for deployment of a prosthesis at a junction of a main lumen and at least one branch lumen. The introducer comprises an outer sheath having a distal end, an axial guide wire slidable within the outer sheath, at least one peripheral guide wire slidable within the outer sheath, and a nose cone located at the distal end of the outer sheath. The nose cone has a periphery, an axial conduit slidable over the axial guide wire, and at least one peripheral channel spaced apart from the axial conduit for receiving one of the peripheral guide wires. Each peripheral channel may be open to the periphery of the nose cone and may provide communication between an interior of the introducer and the lumen when the nose cone is positioned at the distal end of the sheath. Each peripheral guide wire may comprise an expandable balloon at its distal end.
The introducer may further comprise a trunk deployment catheter and at least one peripheral deployment catheter. The trunk deployment catheter is concentric with the axial guide wire and has at least one inflatable deployment balloon at its distal end. Each peripheral deployment catheter is concentric with one of the peripheral guide wires and has at least one inflatable deployment balloon at its distal end.
The invention also comprises a nose cone for use with an introducer for insertion of a prosthesis in a lumen. The nose cone defines an axial conduit for receiving a first guide wire and at least one peripheral channel spaced apart from the axial conduit for receiving a second guide wire. The nose cone typically has a periphery and each peripheral channel is open to the periphery of the nose cone. The nose cone may comprise two peripheral channels that may be diametrically opposed.
The invention also comprises a unitary prosthesis for deployment in a distal location positioned at a junction of a main lumen and at least one branch lumen. The prosthesis comprises a trunk section and at least one arm section extending radially from the trunk section. The arm section may be approximately perpendicular to the trunk section. The unitary prosthesis may comprise two arm sections, such as for deployment at the junction between the aorta and the renal arteries.
The unitary prosthesis may comprise a graft and at least one stent. The stent may comprise a distal trunk stent portion expandable for deployment in a distal portion of the main lumen distal the branch lumen, a proximal trunk stent portion expandable for deployment in a proximal portion of the main lumen proximal the branch lumen, and at least one branch stent portion expandable for deployment in one of the branch lumen. The distal trunk stent portion, the proximal trunk stent portion, and each branch stent portion may each comprise separate stents.
The invention also comprises a method for implanting a unitary prosthesis in a distal location at a junction of a main lumen and at least one branch lumen. The prosthesis to be implanted comprises at least one stent and has a trunk for implantation into the main lumen and at least one arm for implantation into the branch lumen. The method comprises providing an introducer comprising an outer sheath, an axial guide wire and at least one peripheral guide wire slidable within the outer sheath, a nose cone at a distal end of the outer sheath, a trunk deployment catheter concentric with the axial guidewire and having at least one inflatable deployment balloon, and at least one arm deployment catheter concentric with the peripheral guide wire and having at least one inflatable deployment balloon. The nose cone has an axial conduit slidable over the axial guide wire and at least one peripheral guide channel each for receiving one of the peripheral guide wires. Each peripheral guide wire comprises an inflatable anchor balloon at its distal end. The prosthesis is provided inside the outer sheath with the trunk mounted over the axial guide wire and at least one trunk stent portion mounted over each inflatable deployment balloon of the trunk deployment catheter. Each arm is mounted over one of the peripheral guide wires and at least one arm stent portion is mounted over each inflatable deployment balloon of each arm deployment catheter.
The introducer is fed into the lumen until reaching an implantation position adjacent the branch lumen. The introducer is maintained in the implantation position while advancing each peripheral guide wire distally through one of the peripheral channels of the nose cone until each wire is positioned at a sufficient depth within the corresponding branch lumen. Each anchor balloon on each peripheral guide wire is then inflated to fix the wire in a set position, and the prosthesis is advanced over the axial and peripheral guide wires until each arm of the prosthesis is positioned at a sufficient depth within the branch lumen. Then, the deployment balloons are inflated to expand at least the trunk and arm stent portions of the prosthesis to implant the prosthesis. The method may be used to repair an aneurysm.
The invention also comprises a method for implanting a modular prosthesis comprising a trunk module for implantation into the main lumen and at least one arm module for implantation into the branch lumen. The trunk module comprises at least one stent and at least one arm fitting. The arm module is adapted to interconnect with the arm fitting of the trunk module and comprises at least one stent.
The method initially comprises introducing a first introducer into the main lumen until reaching a first implantation position adjacent the branch lumen. The first introducer comprises an outer sheath, an axial guide wire slidable within the outer sheath, a nose cone at a distal end of the outer sheath, and a trunk deployment catheter. The nose cone has an axial conduit slidable over the axial guide wire. The trunk deployment catheter is concentric with the axial guidewire and has at least one inflatable deployment balloon. The modular prosthesis is mounted inside the outer sheath with the trunk module mounted over the axial guide wire and at least one trunk stent portion mounted over each inflatable deployment balloon of the trunk deployment catheter.
The nose cone is advanced distally to a location distal of the junction of the main lumen with the branch lumen and the trunk module is implanted with each arm fitting aligned with a corresponding branch lumen. The trunk section deployment balloons are inflated to expand the trunk stent portions. Then, a second introducer is introduced into the lumen to a second implantation position. The second introducer comprises an outer sheath, an axial guide wire and at least one peripheral guide wire slidable within the outer sheath, a nose cone at a distal end of the outer sheath, a trunk deployment catheter concentric with the axial guidewire and having at least one inflatable deployment balloon, and at least one arm deployment catheter concentric with the peripheral guide wire and having at least one inflatable deployment balloon. The nose cone has an axial conduit slidable over the axial guide wire and at least one peripheral guide channel each for receiving one of the peripheral guide wires. Each peripheral wire comprises an inflatable anchor balloon at a distal end thereof. Each arm module is mounted over one of the peripheral guide wires and at least one arm stent portion of each arm module is mounted over each inflatable deployment balloon of each arm deployment catheter.
The second introducer is maintained in the implantation position while advancing each peripheral guide wire distally through one of the peripheral channels of the nose cone and through one of the arm fittings in the implanted trunk module until each peripheral guide wire is positioned at a sufficient depth within the corresponding branch lumen. Then, each anchor balloon on each peripheral guide wire is inflated to fix the wire in a set position. Each arm module is then advanced over one of the peripheral guide wires until each arm module is positioned at a sufficient depth within the branch lumen and in an interlocking position with one of the arm fittings of the trunk module. Finally, each arm deployment balloon is inflated to expand at least the arm stent portions of each arm module to implant the arm module within the branch lumen and within the corresponding arm fitting of the trunk module.
The invention also comprises a method for implanting at a junction of a main lumen and at least one branch lumen, a prosthesis comprising at least one portion for implantation into the branch lumen. The method comprises the steps of providing an introducer comprising an outer sheath, an axial guide wire and at least one peripheral guide wire slidable within the outer sheath, and a nose cone at a distal end of the outer sheath. The nose cone has an axial conduit slidable over the axial guide wire and at least one peripheral guide channel for receiving the peripheral guide wire. The peripheral wire comprises an inflatable anchor balloon at its distal end. The introducer is introduced into the lumen until reaching an implantation position adjacent the branch lumen. The introducer is maintained in the implantation position while advancing the peripheral guide wire distally through the peripheral channel of the nose cone until the wire is positioned at a sufficient depth the branch lumen. Then, the anchor balloon is inflated to fix the peripheral guide wire in a set position. The prosthesis is advanced over the peripheral guide wire until at least a portion of the prosthesis is positioned at a sufficient depth within the branch lumen, and then at least a portion of the prosthesis is expanded, such as by balloon expansion, for implantation in the branch lumen.